Fuel burner



Oct. 25, 1932. w. A. WOODESON FUEL BURNER Filed Sept. 4, 1928 2Sheets-Sheet l Oct. 25, 1932. w. A. WOODESON FUEL BURNER Filed Sept. 4,1928 2 Sheets-Sheet 2 in liquid,

Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE WILLIAM ARMSTRONGWOODESQN, OF GATESHEAD-ON-TYNE, ENGLAND, ASSIGNOR TO CLARKE CHAPMAN 86COMPANY, LIMITED, 013 GATESHEAD-ON-TYNE, ENGLAND,

AND TO SAID WILLIAM ARMSTRONG; WQODESON FUEL BURN-ER,

Application filed September 4, 1928, Serial No. 303,859, and in GreatBritain January 19, 1928.

This invention relates more particularly to burners of the kind in whicha casing constitutin g a mixing chamber surrounds the delivery end of afuel supply pipe and airenters between such pipe and easing prior toencountering means employed to produce an intimate mixing of the fueland air as well as retardation of velocity. The invention isparticularly applicable to burners of this kind suitable for the firingof furnaces with pulverized fuel, although also intended to apply toburners for dealing with fuels in general gaseous or colloidalconditions.

7 In some burners additional air is supplied to the mixture of air andfuel whichhas already been established from the sources referred to, asfor example, from a space between the mixing chamber which surrounds thefuel pipe end and an outer casing having an inwardly tapering mouthpiece whereby the air emerging. from the passage, is caused to take aninward or converging line of travel in order to reduce the velocity ofthemixture.

The object of the invention is to eflect improvements and ensure thatthe combustion of the fuel may be better achieved as early as possibleafter leaving the burner, to which end the invention includes novelprovisions for the admixture ofsecondary air with the air and fuelmixture pr marily formed in the mixing chamber. The invention alsocontemplates the provision of means for adding tertiary air to themixture of fuel, primary air and secondary air issuing from'the burnerthe tertiary air being so directed into the stream of mixture as toreduce the velocity thereof. 7 V

But in order that the invention may be more readily understood andeasily carried into effect it will be further described with the aid ofthe accompanying drawings which illustrate two constructional forms ofburner embodying the improvements. Of these drawings :Fig. 1 is alongitudinal section of one construction, Figs. 2 and 3 beingrespectively front and rear elevations thereof, certainsv parts in Fig.3 being in section. Fig.

4 is a view, partly in section, of a detail of deflector 1'0 and thefueldischarge or supply Fig. 1. Fig. 5 is a view similar to Fig. 1showing a simplified construction.

In the invention the burner comprises a member 1 formed with a series ofair inlet holes 2 or ducts at or near the extreme end where the mixtureof fuel and air leaves the burner. inclined to the axis of the burner,their axes, for example, being on elements 3 of an imaginary cone havingits apex beyond the discharge orifice of the burner. The said holes orducts may be of elongated cross section and so arranged in the burnermouth as to impart a whirling motion to the issuing air, th s being thepreferred form and that illustrated. The holes or ducts 2 maycommunicats with an air belt constituted by a space 4 between the majorpart 1 of the burner and an outer casing 5. The eifect of the holes or.ducts 2 according to the invention is to disrupt the form of the streamwhich without them naturally issues from the burner whereby it is spreadimmediately in front of the bu rner.

The mixing chamber is shown as equipped with a. deflector 10 comprisinginclined vanes EEO 1arranged to give a whirling motion to the ue Inaddition to the disruptingholes 2 referredto, the deflector 10 of theburner is so constructed that air, for example, can be admitted thereto,as by making one or more of These holes or ducts 2 are suitably thevanes 10 hollow and providing the same 7 .with air discharge apertures13, Figs. 2 and space.4 forward- 7 4, to discharge 'air from the ly ofthe burner. g

, The burner shown in Figs. lto 4 is a compact and easily regulatedconstructional form in which the space 4 constituting the secondary airchamber has a duct 14 leading to a hood 15 with lateral air branch 16arranged to enclose a hit and miss or other suitable regulating device17 controlling admission of air to the inner casing before the deflectoris encountered, the said duct 14 being provided with means, such asa'slide'18, so that the proportionof air which passes through V thedi'sruptingholes 2 and deflector 10 via the hit and miss regulator 17can be varied.

.At a convenient .position,-:say between the pipe 19,, one or moreupwardly directed holes 20 may be formed in the inner casing 1 at thebottom thereof so that air may blow in and somewhat lift the stream ofprimary coal and air and so prevent or minimize the tendency for part ofthe fuel to spill instead of being carried through the burner, whichtendency frequently exists when the coal and air mixture is deliveredthrough the supply pipe 19 at a low velocity.

In Fig. 5 there is shown a modification in which when the burner is tobe fitted to, say, a boiler casing, the outer casing 5 may be formedwith a suitable flange 6 adapted to be bolted to the boiler casing, 7being lateral air inlet openings located to the rear of the flange 6,considering the discharge end to be the front. The burner proper maythen be fixed to the outer casing 5 so that it can be separatelydisconnected therefrom with facility as by bolting together the flanges8, 9. In this modification further the deflector 10 has a centralchamber or hollow hub 11 between which and the space 4 connection isestablished through passages 10 in the vanes 10 holes 12 being formedbetween the vanes through which holes air from the chamber 11 isdirected.

As will be obvious the pipe 19 may be adapted to be fed with powderedfuel either alone or in conjunction with liquid fuel, or with powderedfuel after starting with liquid fuel and if so desired the secondary airadmitted through the disrupting holes 2, the deflector 10, or both,might be enriched with a combustible.

What I claim is 1. A burner of the kind herein referred to, comprising amixing chamber, means for introducing fuel into such mixing chamber,means for admitting air to said chamber in the vicinity of said fuelinlet means and a vaned deflector disposed within said chamber directlyin the path of the combining streams of fuel and air through the chamberso as to constrain said combining streams to pass wholly between thevanes, said deflector eing externally shaped to promote intermixture ofsaid streams and including hollow vanes connecting a source of secondaryair supply with secondary air discharge orifices opening directly intothe mixing cham- 2. A burner of the kind herein referred to, comprisinga mixing chamber, means for introducing fuel into such mixing chamber,means for admitting air to said chamber in the vicinity of said fuelinlet means, a vaned deflector disposed within said chamber directly inthe path of the combining streams of fuel and air through the chamber soas to constrain said combining streams to pass wholly between the vanes,said deflector being externally shaped to promote intermixture of saidstreams and including hollow vanes connecting a source of secondary air'mary mixture of air and fuel emerging besupply with secondary airdischarge orifices opening directly into the mixing chamber and meansfor adding tertiary air to the mixture emergent from the vaned deflectorthrough the mouth of the burner.

3. A burner of the kind herein referred to, comprising a mixing chamber,means for introducing fuel into such mixing chamber, means for admittingair to said. chamber in the vicinity of said fuel inlet means, a vaneddeflector disposed within said chamber directly in the path of thecombining streams of fuel and air through the chamber so as to constrainsaid combining streams to pass wholly between the vanes, said deflectorbeing externally shaped'to promote intermixture of said streams andincluding hollow vanes connecting a source of secondary a1r supply withsecondary a1r discharge orifices opening directly into the mixing cham-1 ber and, at the mouth of the burner, means for projecting air with awhirling motion into the stream of mixture emergent from the burner.

4:. A burner according to claim 1 characterized by the hollow vanes ofthe deflector having frontal air discharge openings arranged todischarge the secondary air substantially in the direction taken by thepritween the vanes and passing to the mouth of the burner.

5. A burner according to claim 1 characterized by the hollow vanes ofthe deflector communicating with air outlet openings arranged in therear part of the deflector so as to discharge the secondary air into themixing chamber in a direction transverse to the direction of flow of themixture through said chamber to the deflector vanes.

6. In a burner of the kind herein referred to, a mixing chamber, an airchamber to the rear of said mixing chamber, means for introducing fuelinto the rear end of said mixing chamber so that it flows therealong,

means for admitting air to said mixing chamber in the vicinity of thefuel inlet thereto and an auxiliary connection from said air chamber tosaid mixing chamber, said auxiliary connection comprising means forjetting air upwardly intothe current through the mixing chamber so as'tolift the fuel particles in such current.

Signed at Newcastle-on-Tyne, this third day of August, 1928.

WILLIAM ARMSTRONG WOODESON.

England,

